Exercise treadmill with adjustable slope

Abstract

An exercise treadmill in which the slope of an endless belt is varied by changing the height of one end of a base frame by means of a swing frame having a vertically adjustable pivot axis. The swing frame is movable from an active treadmill supporting position to an inactive condition where the pivot axis can be changed.

I claim: 
     
       1. An exercise treadmill comprising: a frame assembly including an elongated base frame and a stop unit, said base frame having front and back ends and lateral sides, said stop unit reaching upwardly from the base frame adjacent the front end of the frame assembly;   an endless belt operatively mounted on said frame assembly and having an upper run arranged to move rearwardly with respect to the baes frame when operating;   two laterally spaced and aligned fulcrum members mounted on the frame assembly and each presenting a set of vertically spaced fulcrums interconnected by a transferway and located below the reach of the stop unit;   a swing frame having an aligned pair of laterally spaced trunnions interfitting with said fulcrum members to be movable selectively from fulcrum to fulcrum of said sets of fulcrums via the transferways, and having a pair of laterally spaced group engaging wheels spaced below the trunnions such that the front end of the base frame is raised at different elevations when the trunnions register with different of said fulcrums;   said swing frame engaging the stop unit above the level of the fulcrum members when in an active position whereat the wheels engage the ground forwardly of the stop unit and trunnions to establish the elevation of the front end of the frame assembly by the fulcrums selected for the trunnions, said swing frame being swingable forwardly at the top to an inactive position whereat the wheels engage the ground behind the transferway so that the trunnions can be moved rearwardly into the transferway and shifted in elevation into another selected fulcrum whereupon the swing frame can be swung rearwardly at the top into active position in engagement with the stop unit.   
     
     
       2. An exercise treadmill according to claim 1 in which said stop unit has a laterally spaced pair of upright members engaged by said swing frame when the swing frame is in its active position. 
     
     
       3. An exercise treadmill according to claim 2 in which said swing frame has spring clips interfitting with said upright members. 
     
     
       4. An exercise treadmill according to claim 1 in which said stop unit has a laterally spaced pair of upright members connected by a top member, and said swing frame includes a pair of legs on which said trunnions are mounted and includes an upper cross-member extending between said legs and arranged to engage said upright members when the swing frame is in its active position. 
     
     
       5. An exercise treadmill according to claim 4 in which said pair of legs slope forwardly from said upper cross-member toward their lower ends when said swing frame is in its active position. 
     
     
       6. An exercise treadmill according to claim 4 in which said transferways slope forwardly from their upper ends toward their lower ends, and said swing frame slopes forwardly from said upper cross-member toward said wheels when the swing frame is in its said active position. 
     
     
       7. An exercise treadmill according to claim 4 in which said swing frame has an axle for said wheels extending between said legs adjacent the lower end thereof, said axle being arranged to pass beneath the forward end portion of said base frame while the swing frame is swinging between its active and inactive positions. 
     
     
       8. An exercise treadmill according to claim 1 in which said base frame has a normally inactive front ground support spaced behind the rotary axis of said wheels when said swing frame is in its inactive position, said front ground support being arranged to engage the ground when the swing frame is in its inactive position and to be raised above the ground when the swing frame is in its active position. 
     
     
       9. An exercise treadmill according to claim 8 in which said swing frame has an axle for said wheels which is arranged to pass beneath the forward end of said base frame while the swing frame is moving between its active and inactive positions. 
     
     
       10. An exercise treadmill according to claim 1 in which said swing frame slopes downwardly in the forward direction from said trunnions to the rotary axis of said wheels when the swing frame is in its active position and slopes downwardly in the rearward direction from said trunnions to said rotary axis when the swing frame is in its inactive position.